osh Ramsay (vocals/guitar) formed a band called Ramsay Fiction with friends Steve Marshall, Morgan Hempsted, Trevor Spilchen, and Erik Scott as well as his sister, Sara, as a teenager in high school. After being kicked out of high school for drug addiction and the disbanding of the act, he would later form the current Marianas Trench with high-school friend Matt Webb (guitars/piano/vocals/keyboard), and found drummer via Ian Casselman's want ad in the Georgia Straight. Casselman, in turn recruited his roommate bassist Mike Ayley. The name "Marianas Trench" came about because "all the good band names were taken". After persistence, they were eventually signed to '604 Records', owned by Chad Kroeger of Nickelback, and Jonathan Simkin of Simkin Management; their pop-punk sound influenced by the Motown sounds of the 1960s and 1970s, specifically The Jackson 5.
As their first act, the band recorded and released a self-titled EP in 2002. It contained songs which would later be added onto their debut album, Fix Me (2006). Although named "Fix Me", the title track was removed and left as a single.
Masterpiece Theatre, Marianas Trench's follow-up in 2009, was a kind of concept album with the title track coming in three parts over the album, the final component quotes each previous song in the album as well as incorporating rhythms, melodies, and concepts from the other tracks; the album eventually went platinum in Canada.
On September 23, 2010, Marianas Trench played their first ever American show, at the Bowery Electric in Manhattan.
In 2010, the band played five free shows at the 2010 Winter Olympics in Vancouver and one in Surrey, BC.
The album Ever After followed in 2011.
On April 10, 2013, Marianas Trench announced that they had signed with 'Cherrytree Records' and 'Interscope Records', for releases outside of Canada.
Astoria followed in 2015. 2017 would see them performing at the famed Sound of Music festival in Burlington, Ontario.